The mass flow rate of liquid being poured from a vessel is an important parameter in a number of processes, such as the casting or the atomization of liquid metals. Improved process control can be provided with an accurate, substantially instantaneous measurement of the liquid metal flow rate poured from the vessel. However, conventional flow rate sensors such as venturi meters, ultrasonic probes, turbine sensors, and vibrating tube mass flow meters are unsuitable for measuring the flow rate of corrosive or high temperature liquids, such as molten metals. Therefore, there is a need for an apparatus for measuring the flow rate of aggressive, corrosive, or high temperature liquids.
To meet this need the National Institute of Standards and Technology has initiated a program to develop a method and apparatus utilizing an eddy current sensor for measuring the flow rate of liquid metal. For example, see "Eddy Current Liquid Metal Flow Rate Sensor," L. C. Phillips, A. H. Kahn, NIST/Industrial Consortium on Intelligent Processing of Rapidly Solidified Metal Powders by Inert Gas Atomization, Semi-Annual Report, Mar. 1 to Aug. 31, 1992, pp. 13-17, National Institute of Standards and Technology, Gaithersburg, Md.
An aspect of this invention is to provide a method and apparatus for measuring the flow rate of a liquid from a continuously filled vessel having a pouring channel.
Another aspect of this invention is to provide a method and apparatus for measuring the mass flow rate of aggressive, corrosive, or high temperature liquids from a vessel having a pouring channel.